This relates to electronic devices such as cellular telephones and, more particularly, to methods for handling packet switched and circuit switched traffic in an electronic device.
Electronic devices such as cellular telephones contain wireless circuitry such as radio-frequency transceiver integrated circuits and associated wireless baseband integrated circuits. These wireless baseband integrated circuits may be used in handling wireless voice and data communications.
Wireless traffic for an electronic device such as a cellular telephone typically includes circuit switched (CS) traffic and packet-switched (PS) traffic. Circuit switched traffic commonly includes voice calls, but can also include data. Packet-switched traffic commonly includes data, but can also include voice (e.g., voice over internet protocol phone calls).
Examples of circuit switched wireless protocols include 3G protocols such as Universal Mobile Telecommunications System (UMTS) and Code Division Multiple Access (CDMA) 1xRTT and 2G protocols such as Global System for Mobile Communications (GSM). Examples of packet switched wireless protocols include 4G protocols such as the Long Term Evolution (LTE), 3G protocols such as Evolution-Data Optimized (EV-DO) and High Speed Packet Access (HSPA), and 2G protocols such as Enhanced Data Rates for GSM Evolution (EDGE) and General Packet Radio Service (GPRS).
Modern wireless integrated circuits such as 4G wireless integrated circuits that support LTE protocols often offer legacy support for 3G/2G services. Using 4G wireless integrated circuits to support legacy services can, however, be inefficient, because the 4G wireless integrated circuits are not always as optimized as the 3G/2G chips when performing 3G/2G functions.
It would therefore be desirable to provide improved ways in which to support wireless communications in electronic devices.